First, I put white clay underneath to hold my form and prevent it from rolling. I did this by making a valley. Then I put blobs of clay around the piece and started building up on that. I leveled the clay using a tool and brought the level down to midway of the piece. This was going to be my parting line. Once the clay portion was done, I cut up some foam core board and used hot glue to build walls around the clay. If there was a gap where the clay meets the inside of the wall, I just applied more clay to fill the gap and scraped it to be level with the rest of the clay. Next, I used the end of a tool to create registration marks to act as “keys” for alignment. Afterwards, I sprayed mold release inside the box as well as prepared and poured the first half of the silicone mold into the box.